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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Brandsäkerhet ur hemtjänstens perspektiv : En enkätstudie med Sveriges hemtjänster

Hansson, Petter January 2021 (has links)
9 av 10 bränder där personer omkommer inträffar i bostäder, där. Personer i åldersgruppen 80 år eller äldre är överrepresenterade. Visionen för den svenska nationella strategin för att stärka brandskyddet för individen är att “ingen ska omkomma eller skadas allvarligt till följd av brand”. Delmålsättningen för visionen var att antalet omkomna och allvarligt skadade i bränder ska minska med en tredjedel mellan år 2010 och 2020. När individer bor i sina egna hem, så kallat ordinärt boende, förutsätter bygglagstiftningen att personer själva sätter sig i säkerhet i händelse av brand. Då detta är svårt för äldre med funktionshinder, har MSB har publicerat ett exempel på checklista för kommuner att använda som mall vid riskinventering hos brukare. Syftet med rapporten är att undersöka hur kommunal och privat hemtjänst arbetar med brandskyddsarbete. Men även om synen på brandskydd inom hemtjänsten är olika beroende på vart i landet respondenten är verksam och vilken arbetsform hen har. Metoden som valdes för arbetet var enkätstudie samt litteraturstudie. Enkäten delades upp i olika spår, beroende på om respondenten arbetade ute hos brukare eller inte arbetade ute hos brukare. Målet var att alla enhetschefer (chefer över hemtjänstgrupper) i Sverige skulle få förfrågan att delta i studien. Resultatet visar att majoriteten av respondenterna anser att brandskydd inte är hemtjänstens ansvarsområde. Det pekar även på att det var en skillnad på synen på brandskydd beroende på om respondenten arbetade ute hos brukare eller om hen inte gjorde det. Där respondenter som arbetade ute hos brukare i större utsträckning kontrollerade och jobbade med brukarnas brandskydd än de respondenter som inte arbetade ute hos brukare. Dock var antalet respondenter som arbetade ute hos brukare lägre än de som inte arbetade ute hos brukare. Den visar även att respondenternas syn på brandskydd skiljer sig geografiskt. Detta kunde utgöras av exempelvis användandet av en checklista för riksinventering med avseende på brandskydd, som användes mer frekvent inom vissa regioner än andra. De slutsatser som kan dras av arbetet är att ansvaret för de äldre som inte kan se efter sitt eget brandskydd inte är specificerat. Enligt lagen om skydd mot olyckor så är det den enskildes ansvar att se över sitt brandskydd om hen bor i ordinärt boende. Men om personen inte själv kan göra det, exempelvis på grund av demens eller funktionshinder så finns det ingen klar bild om vem som ska göra det. Socialtjänstlagen kan tolkas så att det är kommunernas ansvar att se över den äldre befolkningen inom kommunen. Dock specificeras brandskydd inte inom lagen. / 9 out of 10 fires in which people die occur in their homes, there. People in the age group 80 years or older are overrepresented in deaths caused by fire. The vision of the Swedish national strategy for strengthening fire protection for the individual is that "no one should die or be seriously injured as a result of fire". The sub-goal for the vision was that the number of fatalities and serious injuries in fires should decrease by one third between 2010 and 2020. When individuals live in their own homes, so-called ordinary housing, the building legislation presupposes that people themselves put themselves in safety in the event of a fire. As this is difficult for the elderly with disabilities, MSB has published an example of a checklist for municipalities to use as a template for risk inventory for individuals. The purpose of the report is to investigate how municipal and private home services work with fire protection work. But even if the view of fire protection in the home care service is different depending on where in the country the respondent is active and what form of work he has. The method chosen for the work was a questionnaire study and a literature study. The questionnaire was divided into different tracks, depending on whether the respondent worked out with users or did not work out with users. The goal was that all unit heads in Sweden would be asked to participate in the study.   The results show that the majority of the respondents believe that fire protection is not the home service's area of ​​responsibility. It also shows that there was a difference in the view of fire protection depending on whether the respondent worked out with patients or did not. Where respondents who worked out at users to a greater extent controlled and worked around the users' fire protection than the respondents who did not work out at users. However, the number of respondents who worked out at users was lower than those who did not work out at users. It also shows that the respondents' views on fire protection differ geographically. This could consist of, for example, the use of a checklist for national inventory with regard to fire protection, which was used more frequently in some regions than others.  The conclusions that can be drawn from the work are that the responsibility for the elderly who cannot look after their own fire protection is not specified. According to the law on protection against accidents, it is the individual's responsibility to review their fire protection if they live in ordinary housing. But if the person cannot do it himself, for example due to dementia or disability, there is no clear picture of who should do it. The Social Services Act may indicate that it is the municipalities' responsibility to review the elderly population within the municipality, but nothing is printed out exactly regarding fire protection.
2

EXPERIMENTS, DATA ANALYSIS, AND MACHINE LEARNING APPLIED TO FIRE SAFETY IN AIRCRAFT APPLICATIONS

Luke N Dillard (11825048) 11 December 2023 (has links)
<div>Hot surface ignition is a safety design concern for serval industries including mining, aviation, automotive, boilers, and maritime applications. Bleed air ducts, exhaust pipes, combustion liners, and machine tools that are operated at elevated temperatures may be a source of ignition that needs to be accounted for during design. An apparatus for the measurements of minimum hot surface ignition temperature (MHSIT) of 3 aviation fluids (Jet-A, Hydraulic Oil (MIL-PRF-5606) and Lubrication Oil (MIL-PRF-23699)) has been developed. This study expands a widely utilized database of values of MHSIT. The study will expand the current range of design parameters including air temperature, crossflow velocity, fluid temperature, global equivalence ratio, injection method, and the effects of pressure. The expanded data are utilized to continue the development of a physics-anchored data dependent system and machine learning model for the estimation of MHSIT.</div><div><br></div><div>The aviation industry, including Rolls Royce, currently use a database of MHSIT values resulting from experiments conducted in 1988 at the Air Force Research Laboratory (AFRL) within the Wright Patterson Air Force Base in Dayton, OH. Over the three decades since these experiments, the range of operating conditions have significantly broadened in most applications including high performance aircraft engines. For example, the cross-stream air velocities (V) have increased by a factor of two (from ~3.4 m/s to ~6.7 m/s). Expanding the known database to document MHSIT for a range of fuel temperatures (TF), air temperatures (TA), pressure (P) and air velocities (V) is of great interest to the aviation industry. MHSIT data for current aviation fluids such as Jet-A and MIL-PRF-23699 (lubrication oil) and their relation to the design parameters have recently been under investigation in a generic experimental apparatus. </div><div><br></div><div>The current work involves utilization of this generic experimental apparatus to further the understanding of MHSIT through the investigation of intermediate air velocities, global equivalence ratios, injection method, and the effects of pressure. This study investigates the effects of air velocity in a greater degree of granularity by utilizing 0.6 m/s increments. This is done to capture the uncertainty seen in MHSIT values above 3.0 m/s. Furthermore, this study also expands the understanding of the effects of injection method on the MHSIT value with the inclusion of spray injected lubrication oil (MIL-PRF-23699) and stream injected Jet-A. The effects of global equivalence ratio are examined for spray injected Jet-A by modulating the aviation fluid injection rate and the crossflow air velocity in tandem. </div><div><br></div><div>During previous experimental campaigns, it was found that MHSIT did not monotonically increase with crossflow air velocity as previously believed. This new finding inspired a set of experiments that found MHSIT in crossflow to have four proposed ignition regimes: conduction, convective cooling, turbulent mixing, and advection. The current study replicates the results from the initial set of experiments at new conditions and to determine the effects of surface temperature on the regimes. </div><div><br></div><div>The MHSIT of flammable liquids depends on several factors including leak type (spray or stream), liquid temperature, air temperature, velocity, and pressure. ASTM standardized methods for ignition are limited to stagnant and falling drops downward (autoignition) at atmospheric pressure (ASTM E659, ASTM D8211, and ASTM E1491) and at pressures from 218 to 203 kPa (ASTM G72). Past studies have shown that MHSIT decreases with increasing pressure, but the available databases lack results of extensive experimental investigation. Therefore, such data for pressures between 101 to 203 kPa are missing or inadequate. As such the generic experimental apparatus was modified to produce the 101 to 203 kPa air duct pressure levels representative of a typical turbofan engine. </div><div><br></div><div>Machine learning (ML) and deep learning (DL) have become widely available in recent years. Open-source software packages and languages have made it possible to implement complex ML based data analysis and modeling techniques on a wide range of applications. The application of these techniques can expedite existing models or reduce the amount of physical lab investigation time required. Three data sets were utilized to examine the effectiveness of multiple ML techniques to estimate experimental outcomes and to serve as a substitute for additional lab work. To achieve this complex multi-variant regressions and neural networks were utilized to create estimating models. The first data sets of interest consist of a pool fire experiment that measured the flame spread rate as a function of initial fuel temperature for 8 different fuels, including Jet-A, JP-5, JP-8, HEFA-50, and FT-PK. The second data set consists of hot surface ignition data for 9 fuels including 4 alternative piston engine fuels for which properties were not available. The third data set is the MHSIT data generated by the generic experimental apparatus during the investigations conducted to expand the understanding of minimum hot surface ignition temperatures. When properties were not available multiple imputation by chained equations (MICE) was utilized to estimate fluid properties. Training and testing data sets were split up to 70% and 30% of the respective data set being modeled. ML techniques were implemented to analyze the data and R-squared values as high as 92% were achieved. The limitation of machine learning models is also discussed along with the advantages of physics-based approaches. The current study has furthered the application of ML in combustion through use of the MHSIT database.</div>

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